Partially fluorinated cyclic ionic polymers and membranes

ABSTRACT

Ionic polymers are made from selected partially fluorinated dienes, in which the repeat units are cycloaliphatic. The polymers are formed into membranes.

This invention was made with government support under Contract No.DE-FC04-02AL67606 awarded by the U.S. Department of Energy. Thegovernment has certain rights in the invention.

FIELD OF THE INVENTION

Disclosed are ionic polymers made from selected partially fluorinateddienes, in which the repeat units are cycloaliphatic, and monomers usedto prepare such polymers. Also disclosed are membranes made from thesepolymers.

BACKGROUND

It has long been known in the art to form ionically conducting polymerelectrolyte membranes and gels from organic polymers containing ionicpendant groups. Well-known so-called ionomer membranes in widespreadcommercial use are Nafion® perfluoroionomer membranes available from E.I. du Pont de Nemours and Company, Wilmington Del. Nafion® is formed bycopolymerizing tetrafluoroethylene (TFE) withperfluoro(3,6-dioxa-4-methyl-7-octenesulfonyl fluoride), as disclosed inU.S. Pat. No. 3,282,875. Other well-known perfluoroionomer membranes arecopolymers of TFE with perfluoro (3-oxa-4-pentene sulfonyl fluoride), asdisclosed in U.S. Pat. No. 4,358,545. The copolymers so formed areconverted to the ionomeric form by hydrolysis, typically by exposure toan appropriate aqueous base, as disclosed in U.S. Pat. No. 3,282,875.Lithium, sodium and potassium are all well known in the art as suitablecations for the above cited ionomers.

Low equivalent weight is necessary to obtain high conductivity, but thiscould cause poor mechanical properties. One approach to solve theseproblem is to make new cyclic polymers which usually have high glasstransition temperature (“Tg”) and good mechanical properties.

Free radical polymerizations which include nonconjugated dienes (and bisvinyl ethers) usually yield polymers which are crosslinked because ofthe “separate” reaction of each of the double bonds with the freeradicals in the reactions. However, it is known that in some instancesperfluorinated or partially fluorinated compounds containing two suchdouble bonds do not form crosslinked polymers, but form polymerscontaining cyclic structures.

In U.S. Pat. Nos. 6,214,955 and 6,255,543 selected partially fluorinatedmonomers and the corresponding polymers were prepared. However, thesepolymers were not made into films and also did not contain any ionomericsubstituents.

What is needed, therefore, are new cyclic, fluorinated monomers andpolymers that can be formed into conductive films with good mechanicalproperties.

SUMMARY

Disclosed is a polymer, comprising one or more of the repeat units (IA),(IB) or (IC):

wherein R comprises a linear or branched perfluoroalkylene group of 1 to20 carbon atoms, optionally containing oxygen or chlorine; Q is chosenfrom F, —OM, —NH₂, —NHCN, —N(M)SO₂R², —N(CN)SO₂R², —C(M)(CN)₂,—C(M)(CN)(SO₂R²) and —C(M)(SO₂R²)₂; R² is an optionally fluorinated 1 to14 carbon alkyl group, optionally containing ether oxygen linkages, oran optionally fluorinated 6-12 carbon aryl group; and M is independentlyH, an alkali cation, ammonium or substituted ammonium. The polymer canbe a homopolymer or copolymer.

Also disclosed is a membrane and an electrochemical cell comprising thepolymer. The electrochemical cell can be a fuel cell.

DETAILED DESCRIPTION

Disclosed herein are polymers that are useful as cation-exchange resins.The cation-exchange resins are useful in making proton-exchangemembranes for electrochemical cells such as fuel cells and can be usedin any application wherein cation-exchange capacity is desired. Theresins may also be used as electrolytes, electrode binders, sensors,electrolysis cells, in lithium batteries in lithium salt form, and inany application requiring charge-transfer phenomena, such as componentsof light-emitting displays. The polymers described herein can be eitherhomopolymers or copolymers.

Described herein is a polymer comprising one or more of the repeat units(IA), (IB) or (IC):

wherein R comprises a linear or branched perfluoroalkylene group of 1 to20 carbon atoms, optionally containing oxygen or chlorine;

Q is chosen from F, —OM, —NH₂, —NHCN, —N(M)SO₂R², —N(CN)SO₂R²,—C(M)(CN)₂, —C(M)(CN)(SO₂R²) and —C(M)(SO₂R²)₂;

R² is an optionally fluorinated 1 to 14 carbon alkyl group, optionallycontaining ether oxygen linkages, or an optionally fluorinated 6-12carbon aryl group; and

M is independently H, an alkali cation, ammonium or substitutedammonium.

By “alkyl” it is meant a monovalent group containing only carbon andhydrogen, chiral or achiral, connected by single bonds and/or by etherlinkages, and substituted accordingly with hydrogen atoms. It can belinear, branched, or cyclic. By “alkylene” it is meant a divalent alkylgroup.

By “optionally fluorinated” it is meant that one or more of thehydrogens can be replaced with fluorines.

By “perfluorinated alkylene” it is meant a divalent group containingcarbon and fluorine connected by single bonds, optionally substitutedwith ether oxygens or other halogens, and containing two free valencesto different carbon atoms.

The term “copolymer” is intended to include oligomers and copolymershaving two or more different repeating units. A copolymer havingrepeating units derived from a first monomer “X-A-X” and a secondmonomer “X—B—X” will have repeating units (-A-) and (—B—). Thecopolymers described herein can be random or block copolymers.

The practical upper limit to the number of monomeric units in thepolymer is determined in part by the desired solubility of a polymer ina particular solvent or class of solvents. As the total number ofmonomeric units increases, the molecular weight of the polymerincreases. The increase in molecular weight is generally expected toresult in a reduced solubility of the polymer in a particular solvent.Moreover, in one embodiment, the number of monomeric units at which apolymer becomes substantially insoluble in a given solvent is dependentin part upon the structure of the monomer. In one embodiment, the numberof monomeric units at which a copolymer becomes substantially insolublein a given solvent is dependent in part upon the ratio of thecomonomers. For example, a polymer composed of flexible monomers maybecome substantially insoluble in an organic solvent if the resultingpolymer becomes too rigid in the course of polymerization. As anotherexample, a copolymer composed of several monomers may becomesubstantially insoluble in an organic solvent when ratio of rigidmonomeric units to flexible monomeric units is too large. The selectionof polymer molecular weight, polymer and copolymer composition, and asolvent is within the purview of one skilled in the art.

The monovalent cation M can be a single cation or a mixture of differentcations. In one embodiment, the M is K, Na, Li, or H. In anotherembodiment, Q is F, —OM, or —NH₂, and more typically F. In the casewhere Q is F, the polymer can easily be converted to other embodimentsusing means well known in the art. They can be hydrolyzed with basessuch as MOH or M₂CO₃ in solvents such as methanol, DMSO and water. Thehydrolysis is usually carried out at room temperature to 100° C.,preferably at room temperature to 50° C. Treatment with acids such asHNO₃ will give polymers where Q is OM. Reaction with R²SO₂NH₂ andtriethylamine, and subsequent after hydrolysis with acid will givepolymers where Q=NHSO₂R². Other methods known in the art can also beused, such as those disclosed in U.S. Pat. Nos. 6,667,377 and 6,294,289,herein incorporated by reference.

In one embodiment R is (CF₂)_(x) where x=1 to 16, (CF₂)_(y)OCF₂CF₂ wherey=1 to 12, or (CF₂CF(CF₃)O)_(z)CF₂CF₂ where z is 1 to 6, R² is methyl,ethyl, propyl, butyl, or phenyl, each of which may be partiallyfluorinated or perfluorinated. In another embodiment x=1 to 4, y=1 to 4,and z is 1 to 2, and R² is perfluoromethyl, perfluoroethyl, orperfluorophenyl.

In another embodiment, the polymer comprises one or more of the repeatunits (IA′), (IB′) or (IC′):

wherein Q is as defined above but is typically F.

The polymers can be prepared via the free-radical polymerization of oneor more compounds of Formula (II):

wherein R, Q, R², and M are as defined above. In one embodiment R is(CF₂)_(x) where x=1 to 16, (CF₂)_(y)OCF₂CF₂ where y=1 to 12, or(CF₂CF(CF₃)O)_(z)CF₂CF₂ where z is 1 to 6, R² is methyl, ethyl, propyl,butyl, or phenyl, each of which may be partially fluorinated orperfluorinated. In another embodiment x=1 to 4, y=1 to 4, and z is 1 to2, and R² is perfluoromethyl, perfluoroethyl, or perfluorophenyl. Themonovalent cation M can be a single cation or a mixture of differentcations. In one embodiment, the M is K, Na, Li, or H. In anotherembodiment, Q is F, —OM, or —NH₂.

Compounds of Formula (II) can be prepared via the reaction schemeoutlined below:

where R, Q, R², and M are as defined above. The reactions can be done inany suitable solvent or mixture of solvents, including the reactantsthemselves. Suitable solvents include but are not limited to N-methylpyrrolidinone, dioxane, acetic acid, or alcohol. Any peroxide initiatorcan be used, such as but not limited to benzoyl peroxide or potassiumperoxodisulfate. The products at each step can be purified by any knownmeans, such as but not limited to distillation or extraction.

The last step of the reaction is typically run under an inert atmospheresuch as nitrogen. Other metals can be used in place of the Zn metal,such as but not limited to Mg.

In one embodiment, Formulae (II), (III) and (IV) are Formula (IIA),(IIIA), and (IVA) respectfully:

wherein Q is as defined above but is typically F.

The compounds of Formulae (II), (III) and (IV) are useful as monomers orcomonomers for various polymers, including polymers comprising one ormore of the repeat units (IA), (IB) or (IC).

Suitable comonomers include but are not limited to tetrafluoroethylene,hexafluoropropylene, vinylidene fluoride, perfluoro-(methyl vinylether), perfluoro(propyl vinyl ether), methyl vinyl ether, propylene,ethylene, chlorotrifluoroethylene, perfluoro(2,2-dimethyl-1,3-dioxole),methyl vinyl ether, ethylene, and propylene. Any of these comonomers maybe optionally substituted, such as substitution with one or more —SO₂Qgroups.

The polymerization of compounds of Formula (II) to form polymerscomprising one or more of the repeat units (IA), (IB) or (IC) may bedone neat, in aqueous emulsion or suspension, in solution or organicsuspension. They may be done in batch, semibatch or continuousoperations. A free radical polymerization initiator is typically used,such as but not limited to peroxides such as perfluoro(propionylperoxide) (3P), azonitriles such as azobis(isobutylronitrile) (AIBN),and redox initiators such as persulfate-bisulfite. A surfactant can alsobe used, typically a partially fluorinated or perfluorinated surfactant.The surfactant can be anionic, cationic, or nonionic. Suitablesurfactants include, are not limited to, sodium dodecylsulfate, alkylbenzene sulfonates, dextrins, alkyl-ether sulfonates, ammonium sulfates,Triton® surfactants, and fluorinated surfactants such as C8 (ammoniumperfluorooctanoate) Zonyl® fluorosurfactants such as Zonyl® 62, Zonyl®TBS, Zonyl® FSP, Zonyl® FS-62, Zonyl® FSA, Zonyl® FSH, and fluorinatedalkyl ammonium salts such as but not limited to R′_(w)NH(_(4-w))Xwherein X is Cl⁻, Br⁻, I⁻, F⁻, HSO₄ ⁻, or H₂PO₄ ⁻, where w=0-4, where R′is (R_(F)CH₂CH₂)—. Zonyl® fluorosurfactants are available from E. I.DuPont de Nemours, Wilmington, Del., and in general are anionic,cationic, amphoteric or nonionic oligomeric hydrocarbons containingether linkages and fluorinated substituents.

The polymerizations can be performed at any temperature at which thereaction proceeds at a reasonable rate and does not lead to degradationof the product or catalyst. The process is generally run at atemperature at which the selected initiator generates free radicals. Thereaction time is dependent upon the reaction temperature, the amount ofcatalyst and the concentration of the reactants, and is usually about 1hour to about 100 hours.

The polymers can be recovered according to conventional techniquesincluding filtration and precipitation using a non-solvent. They alsocan be dissolved or dispersed in a suitable solvent for furtherprocessing.

The polymers described herein can be formed into membranes using anyconventional method such as but not limited to solution or dispersionfilm casting or extrusion techniques. The membrane thickness can bevaried as desired for a particular application. Typically, forelectrochemical uses, the membrane thickness is less than about 350 μm,more typically in the range of about 15 μm to about 175 μm. If desired,the membrane can be a laminate of two polymers such as two polymershaving different equivalent weight. Such films can be made by laminatingtwo membranes. Alternatively, one or both of the laminate components canbe cast from solution or dispersion. When the membrane is a laminate,the chemical identities of the monomer units in the additional polymercan independently be the same as or different from the identities of theanalogous monomer units of the first polymer. One of ordinary skill inthe art will understand that membranes prepared from the dispersions mayhave utility in packaging, in non-electrochemical membrane applications,as an adhesive or other functional layer in a multi-layer film or sheetstructure, and other classic applications for polymer films and sheetsthat are outside the field of electrochemistry. For the purposes of thepresent invention, the term “membrane”, a term of art in common use inelectrochemistry, is synonymous with the terms “film” or “sheet”, whichare terms of art in more general usage, but refer to the same articles.

The membrane may optionally include a porous support or reinforcementfor the purposes of improving mechanical properties, for decreasing costand/or other reasons. The porous support may be made from a wide rangeof materials, such as but not limited to non-woven or woven fabrics,using various weaves such as the plain weave, basket weave, leno weave,or others. The porous support may be made from glass, hydrocarbonpolymers such as polyolefins, (e.g., polyethylene, polypropylene,polybutylene, and copolymers), and perhalogenated polymers such aspolychlorotrifluoroethylene. Porous inorganic or ceramic materials mayalso be used. For resistance to thermal and chemical degradation, thesupport typically is made from a fluoropolymer, more typically aperfluoropolymer. For example, the perfluoropolymer of the poroussupport can be a microporous film of polytetrafluoroethylene (PTFE) or acopolymer of tetrafluoroethylene. Microporous PTFE films and sheetingare known that are suitable for use as a support layer. For example,U.S. Pat. No. 3,664,915 discloses uniaxially stretched film having atleast 40% voids. U.S. Pat. Nos. 3,953,566, 3,962,153 and 4,187,390disclose porous PTFE films having at least 70% voids. Impregnation ofexpanded PTFE (ePTFE) with perfluorinated sulfonic acid polymer isdisclosed in U.S. Pat. Nos. 5,547,551 and 6,110,333. ePTFE is availableunder the trade name “Goretex” from W. L. Gore and Associates, Inc.,Elkton, Md., and under the trade name “Tetratex” from Tetratec,Feasterville, Pa.

Membrane electrode assemblies (MEA) and fuel cells therefrom are wellknown in the art and can comprise any of the membranes described above.One suitable embodiment is described herein. An ionomeric polymermembrane is used to form a MEA by combining it with a catalyst layer,comprising a catalyst such as platinum, which is unsupported orsupported on carbon particles, a binder such as Nafion®, and a gasdiffusion backing. The catalyst layers may be made from well-knownelectrically conductive, catalytically active particles or materials andmay be made by methods well known in the art. The catalyst layer may beformed as a film of a polymer that serves as a binder for the catalystparticles. The binder polymer can be a hydrophobic polymer, ahydrophilic polymer, or a mixture of such polymers. The binder polymeris typically ionomeric and can be the same ionomer as in the membrane. Afuel cell is constructed from a single MEA or multiple MEAs stacked inseries by further providing porous and electrically conductive anode andcathode gas diffusion backings, gaskets for sealing the edge of theMEA(s), which also provide an electrically insulating layer, graphitecurrent collector blocks with flow fields for gas distribution, aluminumend blocks with tie rods to hold the fuel cell together, an anode inletand outlet for fuel such as hydrogen, and a cathode gas inlet and outletfor oxidant such as air.

EXAMPLES In-Plane Conductivity Measurement

The in-plane conductivity of membranes was measured under conditions ofcontrolled relative humidity and temperature by a technique in which thecurrent flowed parallel to the plane of the membrane. A four-electrodetechnique was used similar to that described in an article entitled“Proton Conductivity of Nafion® 117 As Measured by a Four-Electrode ACImpedance Method” by Y. Sone et al., J. Electrochem. Soc. 143, 1254(1996) that is herein incorporated by reference. A lower fixture wasmachined from annealed glass-fiber reinforced Poly Ether Ether Ketone(PEEK) to have four parallel ridges containing grooves that supportedand held four 0.25 mm diameter platinum wire electrodes. The distancebetween the two outer electrodes was 25 mm, while the distance betweenthe two inner electrodes was 10 mm. A strip of membrane was cut to awidth between 10 and 15 mm and a length sufficient to cover and extendslightly beyond the outer electrodes, and placed on top of the platinumelectrodes. An upper fixture which had ridges corresponding in positionto those of the bottom fixture, was placed on top and the two fixtureswere clamped together so as to push the membrane into contact with theplatinum electrodes. The fixture containing the membrane was placedinside a small pressure vessel (pressure filter housing), which wasplaced inside a forced-convection thermostated oven for heating. Thetemperature within the vessel was measured by means of a thermocouple.Water was fed from a calibrated Waters 515 HPLC pump (WatersCorporation, Milford, Mass.) and combined with dry air fed from acalibrated mass flow controller (200 sccm maximum) to evaporate thewater within a coil of 1.6 mm diameter stainless steel tubing inside theoven. The resulting humidified air was fed into the inlet of thepressure vessel. The total pressure within the vessel (100 to 345 kPa)was adjusted by means of a pressure-control letdown valve on the outletand measured using a capacitance manometer (Model 280E, Setra Systems,Inc., Boxborough, Mass.). The relative humidity was calculated assumingideal gas behavior using tables of the vapor pressure of liquid water asa function of temperature, the gas composition from the two flow rates,the vessel temperature, and the total pressure. The slots in the lowerand upper parts of the fixture allowed access of humidified air to themembrane for rapid equilibration with water vapor. Current was appliedbetween the outer two electrodes while the resultant voltage wasmeasured between the inner two electrodes. The real part of the ACimpedance (resistance) between the inner two electrodes, R, was measuredat a frequency of 1 kHz using a potentiostat/frequency response analyzer(PC41750™ with EIS software, Gamry Instruments, Warminster, Pa.). Theconductivity, K, of the membrane was then calculated asκ=1.00 cm/(R×t×w),where t was the thickness of the membrane and w was its width (both incm).

EXAMPLES Example 1 Preparation of CF₂ClCFClCF₂CFICF₂OCF₂CF₂SO₂F

A mixture of 167 g CF₂ClCFICl and 130 g of CF₂═CFCF₂OCF₂CF₂SO₂F washeated at 200° C. in an autoclave for 30 hrs. Distillation gavefractions at by 26° C./250 mmHg to 27° C./25 mmHg, 114 g, and by 57°C./0.08 mmHg to 61/0.06 mmHg, 144.5 g. The product was then distilledvia spinning band to give 109.2 g of pure product, by 83° C./2.3 mmHg.NMR analysis: ¹⁹F NMR: +45.70 (m, 1F), −62.5 (m, 0.5F), −63.6 (m, 1.5F),−71.8 to −73.5 (m, 1F), −75.6 to −76.7 (m, 1F), −82.6 (s, 2F), −96.8 to−101.5 (m, 1.5F), −105.0 to −106.0 (m, 0.5F). −112.4 (m, 2F), −125.5 (m,0.5F), −129.0 (m, 0.5F), −138.8 (m, 0.5F), −142.6 (m, 0.5F). IR: 1465(s, SO₂F), 1271 to 1121 (vs, C—F) cm⁻¹. Analysis: Calculated forC₇F₁₃Cl₂SO₃I: C, 13.81; F, 40.56; Cl, 11.64; I, 20.84; S, 5.27. Found:C, 13.76; F, 42.06; Cl, 11.25; I, 20.82; S, 5.12.

Example 2 Preparation of AcOCH₂CHICH₂CF(CF₂CFClCF₂Cl)CF₂OCF₂CF₂SO₂F

To a stirred mixture of 5.0 g (0.05 mol) of allyl acetate and 30.4 g(0.05 mol) of CF₂ClCFClCF₂CFICF₂OCF₂CF₂SO₂F from Example 1 was added 0.2g of benzoyl peroxide at 85° C. in N₂. An exothermic reaction occurredand the temperature increased to 120° C. After cooling to 110° C., anadditional 0.1 g of benzoyl peroxide was added and the reaction mixturewas stirred for 30 min. 0.3 g of benzoyl peroxide was then added in afraction of 0.2 g every 30 min. GC (gas chromatography) indicated nostarting materials remained, and the mixture was evaporated at fullvacuum to remove impurity to give 36.1 g (98%) of the pure adduct. NMRanalysis: ¹H NMR: 4.6-4.1 (m, 3H), 3.2-2.8 (m, 2H), −2.1 (m, 3H). ¹⁹FNMR: +45.4 (m, 1F), −62.3 to −63.9 (m, 1.5F), −75.6 to −78.8 (m, 1.5F),−82.5 (m, 2F), −107.5 to −111.0 (m, 2F), −112.4 (m, 2F), −130.6 to−131.3 (m, 1F), −180.2 to −182.6 (m, 1F). IR: 1753 (s, CH₃CO₂), 1463 (s,SO₂F), −1216 to −1149 (vs, C—F) cm⁻¹. HRMS: Calculated forC₁₂H₉O₅F₁₃SCl₂I: 708.8385. Found: 708.8376.

Example 3 Preparation CH₂═CHCH₂CF(CF₂CF═CF₂)CF₂OCF₂CF₂SO₂F

A 200 mL flask was charged with 9.8 g of Zn (0.15 mol), 1.0 g of CuI and50 mL of N-methyl prrolidinone under N₂. Next, 33 g (0.45 mol) ofAcOCH₂CHICH₂CF(CFClCF₂Cl)CF₂OCF₂CF₂SO₂F was added dropwise at roomtemperature. In order to keep the temperature below 30° C. during theaddition the flask was cooled with cool water.

After the addition was complete, the reaction mixture was heated to 80°C. for 1 hr and then the condenser was replaced with a distillationhead. All volatiles were distilled out in full vacuum and the receivercooled with dry ice until half of mixture had distilled. The distillatewas poured into water and the low layer was separated, washed with waterand/or brine for several times. Finally, the crude product was distilledat 10 mmHg to give pure product, by 58° C./1.5 mmHg. NMR analysis: ¹⁹FNMR. −77.2 (dm, J=137.6 Hz, 1F), −77.4 (dm, J=137.6 Hz, 1F). −82.4 (m,2F), −90.8 (dt, J=38.1 Hz, J=6.0 Hz, 1F), −91.0 (dt, J=38.1 Hz, J=6.0Hz, 1F), 106.1 (m, 1F), −112.6 (m, 2F), −180.2 (m, 1F), −186.0 (dm,J=116.8 Hz, 1F). ¹H NMR: 5.95 (m, 1H), 5.20 (m, 2H), 2.80 (m, 2H). RHMS:Calcd for C₁₂H₉O₃F₁₂S (M+C₂H₅—HF, The exact mass measurement was takenwith the M+C₂H₅ peak): 461.0081. Found: 461.0061.

Example 4 Polymerization of CH₂═CHCH₂CF(CF₂CF═CF₂)CF₂OCF₂CF₂SO₂F

A three necked clean flask fitted with a condenser top with a N₂inlet/outlet, a stirring bar and a thermal meter was charged with 15 mLof deionized water and 1 mL of 20% ammonium perfluorooctanoate solution.The solution was bubbled with N₂ for 30 min. 2.0 g ofCH₂═CHCH₂CF(CF₂CF═CF₂)CF₂OCF₂CF₂SO₂F was added to the flask via asyringe under N₂ and ultrasonically mixed to make an emulsion solution.After heating to 80° C., 0.5 mL of solution (made from 24 mg ofpotassium peroxodisulfate in 1 mL of deionized water) was added via asyringe and the flask was kept at 80° C. for 2 hrs. (It was veryimportant to maintain the temperature at 80° C.). An additional 0.5 mLof initiator solution was added and stirred for another 2 hrs. The flaskwas cooled with dry ice until frozen, then was warmed up to roomtemperature. After 5 ml of 20% HNO₃ was added in order to coagulate thepolymer, the mixture was stirred at 90 for 30 min, cooled to roomtemperature, filtered and washed with water for 3 times to give a whitepowder. The powder was dried in a vacuum oven at 100° C. for 4 hrs togive 1.8 g of polymer. DSC (differential scanning calorimetry) indicatedthat the polymer had a T_(m) of 55° C. at first heat and T_(g) of 52° C.at second heat. By TGA (thermal gravimetric analysis), 5% weight loss ofpolymer was 330° C. in air when heated at 10° C./min. IR indicated nodouble bond absorption. ¹H NMR (CF₃Ph): 2.30 to 3.5 (m). ¹⁹F NMR: +42.5(s, 1F), −81.2 to −84.7 (m, 2F), −85.2 (m, 2F), −105.0 to −113.1 (m,2F), −115.0 (s, 2F), −119.8 (m) and −122.8 (m) total 2F. −159.2 to −161(m), −170 (m), −175.7 to −179.0 (m) and −190.1 (m) total 2F. Analysis:calculated for C₁₀H₅F₁₃SO₃: C, 26.55; H, 1.11; F, 54.64; S, 7.07. Found:C, 26.83; H, 1.05; F, 54.68; S, 7.07.

Example 5 Polymerization of CH₂═CHCH₂CF(CF₂CF═CF₂)CF₂OCF₂CF₂SO₂F in F113

A glass tube was charged with 10 mg of Percadox 16N,(bis-4-t-butyl-cyclohexyl)peroxydicarbonate, Akzo Nobel PolymerChemicals LLC Chicago, Ill.) 6 mL of 1,2,2-trichlorotrifluoroethane and1.0 g of CH₂═CHCH₂CF(CF₂CF═CF₂)CF₂OCF₂CF₂SO₂F. After being cooled at−78° C., the tube was evacuated and purged with N₂ for 5 times and thensealed. The sealed tube was heated at 65° C. for 20 hrs. The resultingviscous liquid was poured into hexane. Solid polymer was isolated anddried overnight in a vacuum oven at 100° C. DSC indicated polymer had aT_(m) of 55° C. at first heat and a T_(g) of 52° C. at second heat. ByTGA, 5% weight loss of polymer was 330° C. in air when heated at 10°C./min. ¹H NMR(CF₃Ph): 2.30 to 3.5 (m). ¹⁹F NMR: +42.5 (s, 1F), −81.2 to−84.7 (m, 2F), −85.2 (m, 2F), −105.0 to −113.1 (m, 2F), −115.0 (s, 2F),−119.8 (m) and −122.8 (m) total 2F. −159.2 to −161 (m), −170 (m), −175.7to −179.0 (m) and −190.1 (m) total 2F. Analysis: Calcd for C₁₀H₅F₁₃SO₃:C, 26.55; H, 1.11; F, 54.64; S, 7.07. Found: C, 26.58; H, 0.72; F,53.82; S, 7.31.

Example 6 Preparation of Membrane

1.3 g of the polymer prepared in Example 2 was suspended in 10%(NH₄)₂CO₃ in 1 to 1 methanol and water solution at 50° C. for 2 days.After removal of volatiles, the residue was dried in a 110° C. vacuumoven overnight and then treated with concentrated HCl at 50° C. for 6hrs. 1.1 g of solids were obtained by filtration and dried at 100° C. ina vacuum oven overnight. Polymer was dissolved in methanol, coated ontoexpanded PTFE (poly-tetrafluoroethylene) film and dried first in air andthen at 60° C. in vacuum oven. The conductivity of the sample wasmeasure in-plane at 120° C. under controlled humidity varying from 25%first to 95% at the end. The conductivity values are shown below:

RH % Conductivity (mS/cm) 25 16.6 50 45.3 95 274.1

What is claimed is:
 1. A polymer, comprising one or more of the repeatunits (IA), (IB) or (IC):

wherein R comprises a linear or branched perfluoroalkylene group of 1 to20 carbon atoms, optionally containing oxygen or chlorine; Q is chosenfrom F, —OM, —NH₂, —NHCN, —N(M)SO₂R², —N(CN)SO₂R², —C(M)(CN)₂,—C(M)(CN)(SO₂R²) and —C(M)(SO₂R²)₂; R² is an optionally fluorinated 1 to14 carbon alkyl group, optionally containing ether oxygen linkages, oran optionally fluorinated 6-12 carbon aryl group; and M is independentlyH, an alkali cation, ammonium or substituted ammonium.
 2. The polymer ofclaim 1 wherein Q is F.
 3. The polymer of claim 1 wherein R is (CF₂)_(x)where x=1 to 16, (CF₂)_(y)OCF₂CF₂ where y=1 to 12, or(CF₂CF(CF₃)O)_(z)CF₂CF₂ where z is 1 to 6; and wherein R² is methyl,ethyl, propyl, butyl, or phenyl, each of which may be partiallyfluorinated or perfluorinated.
 4. The polymer of claim 3 where x=1 to 4,y=1 to 4, and z is 1 to 2; and R² is perfluoromethyl, perfluoroethyl, orperfluorophenyl.
 5. The polymer of claim 1 comprising one or more of therepeat units (IA′), (IB′) or (IC′):


6. The polymer of claim 5 wherein Q is F.
 7. The polymer of claim 1which is a copolymer.
 8. The polymer of claim 7 comprising one or morerepeat units derived from a comonomer selected from the group consistingof optionally substituted tetrafluoroethylene, hexafluoropropylene,vinylidene fluoride, perfluoro(methyl vinyl ether), perfluoro(propylvinyl ether), methyl vinyl ether, propylene, ethylene,chlorotrifluoroethylene, perfluoro(2,2-dimethyl-1,3-dioxole), methylvinyl ether, ethylene, and propylene.
 9. The polymer of claim 8 whereina comonomer is tetrafluoroethylene.
 10. A membrane comprising thepolymer of claim
 1. 11. An electrochemical cell comprising the polymerof claim
 1. 12. The electrochemical cell of claim 11 that is a fuelcell.